A 56-year-old woman presents with increased urinary frequency and thirst. Her blood glucose is elevated at 223 mg/dL and hemoglobin A1c is 9.2, consistent with diabetes. She is obese and eats an unhealthy diet. The document defines diabetes mellitus and the differences between type 1 and type 2 diabetes. It discusses common symptoms, diagnostic tests including blood glucose and hemoglobin A1c levels, and treatment options including lifestyle changes, oral medications, and insulin. Complications like diabetic ketoacidosis are also reviewed.